Many sensor packages may require cavities for stress or vibration isolation (i.e., gyroscopes) or to provide acoustic volume. For example, acoustic performance in a micro-electro-mechanical system (MEMS) based microphone device may require an acoustic chamber in the package and an open port to the chamber to receive sound wave input. MEMS devices exist where the port is either on the top or bottom of the package.
In a sensor package that may require a cavity, radio frequency (RF) shielding may be required to protect the package from interference from electromagnetic noise signals. Such designs generally use a formed metal lid or a molded plastic lid with conductive metal plating to form the cavity structure and to provide adequate RF shielding. In some sensor packages, such as in a MEMS microphone, it is desirable to install an acoustic seal to segregate the front and back volume for better single to noise ratio. Current designs either suffer from reduced sensitivity or increased noise as a result of limited back volume, poor or no isolation of back volume, or impeded access to the back volume through a small channel internal to the substrate.
Therefore, a need existed to provide a system and method to overcome the above problem.
Common reference numerals are used throughout the drawings and detailed description to indicate like elements.